Computer users conventionally use image files to create a snapshot of a computer memory, such as a hard drive. One such image file is a Windows Imaging (WIM) file, which is a collection of image files that may or may not contain an operating system (OS) and its components. The WIM image format, which is file-based rather than sector-based, describes the layout of the image files. The WIM image can be used for any number of imaging applications, including the setup and deployment (including upgrades) of an OS (e.g., a Windows OS). Beyond OS setup and deployment, the WIM images can also be used for backing up or restoring a system or volume with data and executable files. Conventional tools and application programming interfaces (APIs) are available for creating and restoring these images to or from volumes or directories on a system.
Known image files, including WIM image files, share two key features, namely: the contents of a stored image file are essentially opaque and image files themselves are static after creation. With respect to the opaque nature of the contents of an image file, once an image file is created, its contents cannot be accessed unless the file is restored in its entirety, or booted, to a system volume or a directory. This restoration of the entire image file can be cumbersome when there is a need to access only a small portion of the contents of the image file (e.g., a small number of files or file identifiers only). For example, a user may wish to verify the contents of an existing image file to ensure that it has the latest binary files. To do so conventionally, the user would need to restore, or boot, the entire image file to a system volume or directory to access the files of interest. This restoration may take considerable time, depending on the number of image files and their sizes.
With respect to the static nature of known image files, conventionally, once an image file is created, its contents cannot be changed or updated. This inability to modify an image file can be a problem in certain scenarios where the capability to modify the contents of an image would be helpful. Conventionally, once an image file is created, the only way to update or apply a patch to files within the image file is to recreate the entire image file with the modifications and then discard the old image file. Generating an entirely new image file can take some time, particularly if the size of the image is large, or if the number of image files that need to be recreated is large. A way to view and/or modify the contents of an image file would be useful.